A robust, self-aligned, polarization independent, pure phase filter was obtained using the intensity dependent refractive index (IDRI) medium, zinc tetraphenyl porphyrin (ZnTPP), a metalloporphyrin. An optical image processor with ZnTPP as the phase filter was designed so that both weak and strong phase objects can be tested with no appreciable design modification. A good phase contrast image with negligible amplitude reduction of the input beam was achieved and the porphyrin as phase filter was found to have several specific advantages over other IDRI media. © 2005 Elsevier B.V. All rights reserved.

C. Vijayan

Department Of Physics

Kaladevi Sendhil

Mahendra Prasad Kothiyal

Aberrations

Image processing

Interferometry

Nonlinear optics

Porphyrins

Thin films

Visualization

4-F IMAGING SYSTEMS

IMAGE-FORMING SYSTEMS

NONLINEAR MEDIUM

PHASE FILTERING

OPTICAL FILTERS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Optics Communications

We demonstrate the use of stable films containing PbS nanocrystals as media for self-adaptive phase filtering in phase contrast imaging of transparent objects by a cost-effective exploitation of nonlinear optical refraction in a simple, all-optical, and self-adjusting 4f imaging system. The optical nonlinearity is characterized by z-scan technique using a continuous wave He-Ne laser as the excitation source. The mechanism of nonlinearity in this case is mainly due to the nonlocal thermo-optical interaction between the laser beam and the sample. The value of nonlinear refractive index coefficient is found to be -3:5 × 10-7 cm2=W. The nanocomposite material shows a thermal lens effect and is a potential candidate for phase contrast imaging. © 2009 Optical Society of America.

Applied Optics

Spatial phase filtering based on the intensity-dependent refractive index of PbS nanocomposite film

Self-organization and other processes of aggregation in metalloporphyrins are of recent interest in view of their scope for several new applications. The technique of photoacoustic spectroscopy is used in the present work to investigate the optical properties of FeTPPCl aggregates on glass substrate. The observed features in the photoacoustic spectrum of the aggregates are compared with those of the porphyrin in solution and powder forms. Spectral shifts and broadening of the bands indicating aggregation as well as well-resolved features of hyper spectra are observed clearly in the photoacoustic spectra. © 2007 Elsevier B.V. All rights reserved.

Materials Letters

Photoacoustic investigations on self-organization effects in metalloporphyrins on glass substrates

Physical Review A

Nonlinear optical measurements using a4fcoherent imaging system with phase objects

Journal of Applied Physics

Self-induced nonlinear Zernike filter realized with optically addressed liquid crystal spatial light modulator

Influence of illuminating beyond the object support on Zernike-type phase contrast filtering

Optics Letters

All-optical image processing by means of a photosensitive nonlinear liquid-crystal film: edge enhancement and image addition–subtraction

Optimal phase contrast in common-path interferometry

Spatial phase filtering with a porphyrin derivative as phase filter in an optical image processor

Journal	Data powered by TypesetOptics Communications
Publisher	Data powered by TypesetSpringer
ISSN	00304018
Open Access	No